It has been recognized that the high temperature combustion of hydrocarbonaceous fuels results in the production of various oxides which when released in the atmosphere results in pollution, smog and other deleterious effects to the environment.
Reduction of pollution and conservation of fuel have focussed largely on the products of automobile exhaust and fossil fuel combustion. Automobile exhaust produces carbon monoxide, hydrocarbons, lead, nitrogen oxides and sulfur oxides in large quantities. Coal and oil burnt for electric power or for other industrial purposes contribute significant amount of particulates to the environment.
A number of approaches are being used and tried in the area of emission control devices; for pollution control in automobiles; removal of pollutants from stack gases of industrial plants and the like.
Those skilled in the art of pollution control are familiar with many catalysts developed for the direct reduction of nitrogen. Sometimes the catalysts are used in the form of supported catalyst which may contain 2-50% of their total weight as oxides of vanadium, molybdenum and/or tungsten.